Planetary Magnification Increments

Here's my situation:

I'm using a 6" f/5 and eliminating some short focal length eyepieces with longer eye-relief options. My current eyepiece/barlow configurations give me planetary magnifications of 160x, 180x 200x, 250x and 300x for exceptional nights. My Midwestern Urban seeing conditions generally limit good seeing nights to 250x max.

Here's my question for die hard planetary observers (particularly Jupiter, Saturn an Mars) - do I need to fill in with something that will give me 225x, or is this not necessary with the 200x and 250x I currently have?

Thanks for any guidance you can provide.

I would say that 225x is not necessary, and really neither is 180x if you have 160x and 200x. In my experience magnification increments of less than 20% results in eyepieces going unused.